Various symptoms point to a compromised inverter board, even though the washer (GE Harmony Profile washing machine WPGT9360E0PL) passes the self-test and the inverter board voltages measure normal when tested as described in the service manual. The washer displayed the standard failure message followed by error codes suggesting the inverter board might be the culprit. I believe the inverter board is failing under load (e.g. washer rotation is erratic and produces an out-of-balance error trying to spin even when empty). The inverter board is discolored in the vicinity of IC300 and a nearby electrolytic capacitor appears to be leaking.

The service manual states

"Look for a burnt IC, labeled IC300, on the
inverter board. Both the resistor and inverter
board should be replaced if the IC300 is
damaged."

I am replacing the inverter board, but the braking resistor however shows no signs of damage and reads about 70.3 ohms as expected when tested. I believe it to be just fine and I have no plans to replace it unless someone can convince me otherwise. Thanks.

Steve

The board is kind of difficult to work on because it is "potted" with some kind of soft transparent glue or resin. I couldn't make out any markings on IC300 (it might be propietary - i.e. unmarked) and I don't know if the markings on the electrolytic capacitor are readble anymore (or check if it might be identical to another capacitor I can read). The quickest solution for me is to acquire a refurbished board (and maybe get my failed board repaired and possibly passed on to someone who needs it if I don't).

Edited by user Wednesday, October 13, 2021 11:42:06 AM(UTC)  | Reason: spelling fix

So I replaced the inverter board and I am still getting the message "The motor is not rotating properly. Check and replace if necessary." I can't find anything wrong with the motor when I check the connectivity between windings - I get about 8 ohms resistance between any two terminals of the lead wire to the stator. It is not clear to me what additional check I can perform on the motor. The stator and rotor assembly are pretty simply - either the motor windings energize when powered or they don't, and the rotor with its fixed magnets doesn't really have much choice but to respond. What am I missing here?

The service manual says to check (1) the house supply voltage (120 VAC is present). (2) Wiring connections (no issue that I can detect). (3) Motor. (4) Hall sensor (It seemed to be operating properly when I checked it previously with the original board installed; I see the voltages between the proper pins when I rotate the drum). (5) Inverter board.

Thanks.